/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.conf.directories;

import org.apache.iotdb.commons.cluster.NodeStatus;
import org.apache.iotdb.commons.conf.CommonDescriptor;
import org.apache.iotdb.db.conf.directories.strategy.*;
import org.apache.iotdb.db.exception.DiskSpaceInsufficientException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

public class FolderManager {
    private static final Logger logger = LoggerFactory.getLogger(FolderManager.class);

    private final List<String> folders;
    private final DirectoryStrategy selectStrategy;

    public FolderManager(List<String> folders, DirectoryStrategyType type)
            throws DiskSpaceInsufficientException {
        this.folders = folders;
        switch (type) {
            case SEQUENCE_STRATEGY:
                this.selectStrategy = new SequenceStrategy();
                break;
            case MAX_DISK_USABLE_SPACE_FIRST_STRATEGY:
                this.selectStrategy = new MaxDiskUsableSpaceFirstStrategy();
                break;
            case MIN_FOLDER_OCCUPIED_SPACE_FIRST_STRATEGY:
                this.selectStrategy = new MinFolderOccupiedSpaceFirstStrategy();
                break;
            case RANDOM_ON_DISK_USABLE_SPACE_STRATEGY:
                this.selectStrategy = new RandomOnDiskUsableSpaceStrategy();
                break;
            default:
                throw new RuntimeException();
        }
        try {
            this.selectStrategy.setFolders(folders);
        } catch (DiskSpaceInsufficientException e) {
            logger.error("All disks of wal folders are full, change system mode to read-only.", e);
            CommonDescriptor.getInstance().getConfig().setNodeStatus(NodeStatus.ReadOnly);
            throw e;
        }
    }

    public String getNextFolder() throws DiskSpaceInsufficientException {
        try {
            return folders.get(selectStrategy.nextFolderIndex());
        } catch (DiskSpaceInsufficientException e) {
            logger.error("All disks of wal folders are full, change system mode to read-only.", e);
            CommonDescriptor.getInstance().getConfig().setNodeStatus(NodeStatus.ReadOnly);
            throw e;
        }
    }
}
